Replies to This Discussion

Permalink Reply by Outhouse Instruments on December 31, 2010 at 2:03am

Look at this way. Sound is vibration. The string vibrates on the bridge, transferring the energy to whatever is under it. That is the point of strongest vibes.

but also depends on what sound you want.

 

 

Matt

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Permalink Reply by Skeesix on December 31, 2010 at 1:57pm

Inside the box, some people put them close to the bridge but on the bass side so it can pick up more bass vibrations. The reason is that since the boxes are shallow compared to a "real" guitar they sound treblier.

In general, the closer to the bridge, the louder it will be. Literally right under the bridge on the outside of the box would be the loudest. The pressure from the bridge/strings would help add volume. This is my favorite spot.

Any kind of damping such as hot glue, wood, rubber, hanky, etc. will help dampen the harsh high frequencies and the tendency to feedback, thus making a more pleasing sound.

Bringing down the impedance closer to the amp impedance is another way to get a better sound out of a piezo.

But as they say, no rules, so if it sounds great to you, that's what counts - have fun experimenting!

 

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Permalink Reply by Gadsden Guitars on January 2, 2011 at 7:25am

i have a question about bar piezo's, for one utilizing a pre-amp would it still  be the best place (under the bridge) even if its just a three stringer?

 

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Permalink Reply by Don Thompson on January 2, 2011 at 9:58am

Let's look at it this way. Practically all guitar builders using piezos place them at that location. Must be a reason for that and there is, it's the best volume with the least feedback problems. Also less handling noise.

Don

Godzilla said:

i have a question about bar piezo's, for one utilizing a pre-amp would it still  be the best place (under the bridge) even if its just a three stringer?

 

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Permalink Reply by Gadsden Guitars on January 2, 2011 at 2:22pm

Cuts down on feedback huh, even if you were to use a skeleton key for a saddle? Jus wonderin'.

Don Thompson said:

Let's look at it this way. Practically all guitar builders using piezos place them at that location. Must be a reason for that and there is, it's the best volume with the least feedback problems. Also less handling noise.

Don

Godzilla said:

i have a question about bar piezo's, for one utilizing a pre-amp would it still  be the best place (under the bridge) even if its just a three stringer?

 

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Permalink Reply by Roger Morin on January 2, 2011 at 3:24pm

Jay at tinyguitars puts down a glob of hot glue then presses the piezo into the hot glue no feed back, I have wned a number of his instruments and I'm well satisfied. I have now place to build living in an apartment that why I buy my instuments

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Permalink Reply by Skeesix on January 2, 2011 at 6:36pm

The location is not really involved with feedback, it's more about the damping material.

On a "real" guitar the bar piezo is embedded in the bridge under the saddle. That would provide damping.

If I were going to use a skeleton key, I would make a sandwich, starting from the top  - skeleton key, thin piece of wood, piezo, then either nothing, or another thin piece of wood, or cork, or mouse pad. The cork or mouse pad would provide additional damping from box noise.

You may be able to do something with skeleton key/hot glue/piezo/hot glue or other combinations, although that's not as pretty looking as wood. Maybe skeleton key/wood/piezo/hot glue.

 

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Permalink Reply by Jerryrig240 on January 3, 2011 at 12:46am

I used hot glue in my new build, and it worked great!!!! I put down some real good hot glue, then put down my peizo, then I hot glued my wire conections and I am very well pleased with the very small amount of feedback, hum, or box and neck noise....so much so, I am going to build another build soon and will use this same method time and time again.

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Permalink Reply by Don Thompson on January 3, 2011 at 3:14am

I have to disagree that location has nothing to do with feedback. A flexible soundboard mounted piezo will for a given volume level feedback sooner than a bridge mounted piezo as you are getting one, more direct string vibrations, two the area the bridge sits on will be stiffer. I can quote several more references:

"feedback even at low levels of amplification.

These days the most popular place to locate a piezo transducer on a guitar is in the bridge, and for flat top guitars the most popular place in the bridge is directly under the saddle.  Here, string tension variations caused by the vibration of the string translate into pressure variations on the saddle, which rests right on top of the transducer.  This placement is less prone to feedback than soundboard placement and also produces a more balanced frequency spectrum.  On the downside, under saddle placement reads more of the sound of the strings themselves, and less of the sound of the entire instrument.  Again, there is always a tradeoff with transducer placement, but this is one that works out well in practice.'

Don

 

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